Note that only one side of the load cell is screwed into each board. This
provides a moment of force, or torque, on the strain gauge rather than just
compression force, which is easier to measure and much more accurate.
For smaller, push-button or disc load cells, you will want to make sure to
screw in the disc to a bottom plate (or surface you are measuring force
against), and center the beam, plate, or whatever else you are wishing to
measure the force of onto the “button” on the top. Usually another plate with
a hole is used to make sure whatever you are measuring is hitting the same
spot on the load cell each time, but it is not necessary.
Make sure to read the datasheet for the load cell you are using and get the
correct screws to fit into it.
• Note: If you are hooking together four of the SparkFun Load Sensors
using the Combinator board, you should position the four load
sensors equidistant from each other, just like the bathroom scales
shown in this tutorial.
Load cell measurements can be off by +/- 5% due to a range of things
including temperature, creep, vibration, drift, and other electrical and
mechanical interferences. Before you install your scale, take a moment and
design your system to allow for easy calibration or be able to adjust the
code parameters to account for these variations.
Hardware Hookup
Page 4 of 10
